1. Field of the Invention
The present invention is directed to portable construction equipment, and more particularly, to sheet bending brakes.
2. Background
The use of some machines calls for supporting a workpiece while presenting it with a particular orientation to the machine. For example, a common bending machine, known as a sheet bending brake (“brake”), is operative to bend a substantially flat workpiece of sheet material. Such sheet material typically are made of aluminum, one or more compositions of vinyl, or the like and are used in siding structures, houses, railings or the like.
In order to bend such a workpiece using a typical sheet bending brake, ordinarily, the workpiece is first positioned upon the brake's clamping surface so that the edges of the workpiece have a desired orientation with respect to the brake. Commonly, a rectangular workpiece is positioned so that its front and rear edges are generally parallel to the front side of the brake.
Such a position allows the typical brake to bend the workpiece along a line that is generally parallel to the workpiece's front and rear edges. It is common for the craftsman of a brake to position the workpiece manually, perhaps with the assistance of a helper, controlling the workpiece's orientation as it is presented to the brake. As the craftsman positions the workpiece upon the brake's clamping surface, he visually estimates, or perhaps determines with the assistance of temporary markings placed upon the workpiece, whether the workpiece is properly oriented or aligned relative to the brake.
Considering that each workpiece is typically a several feet long, proper orientation and alignment operations take an inappropriately long time. Often, as the craftsman approaches one end of the workpiece, the opposite end of the latter may be accidentally moved out of alignment. Accordingly, it would be desirable to simplify these operations by providing, for example, stoppers operative to prevent the workpiece portion from accidental displacement.
Typically, the workpiece must be cut from a coil of continuous sheet of material. This presents a problem as the coil is tightly wound for efficient shipping and storage. Once the retaining tape is removed the coil springs to unwind and is easily damaged or becomes soiled. To obviate this problem, craftsmen may work together—one craftsman unwinds the coil to the desired length of the individual workpiece and the other holds the still wound coil segment. However, this is highly inefficient use of manpower. Thus, it has been suggested that the coil be retained in some fashion while still being able to be unrolled.
One suggestion is to use a cradling device that is positioned on its own legs adjacent to the bending brake. The material is then unrolled, cut and fed one at a time into the bending brake for bending. Problems are inherent with such an arrangement; for example while unwinding the coil, the cradling device may be knocked over; the coil may slip off the coil support and fall on the ground. Since the craftsman usually prepares numerous individual workpieces, recurrent resetting of the cradling device or mounting of the fallen coil considerably slows the craftsman and makes the entire process inefficient. Having the bending brake provided with a means for securing the coil can improve the efficiency of this machine.
Furthermore after unwinding the coil at the desired length and using a cutter to sever the individual workpiece from the rest of the coil, the craftsman has a need to place the workpiece somewhere so as to proceed to cut the next workpiece or perform some other task. Typically, the workpieces end being aggregated on the ground where they are damaged or soiled. Thus, it would be desirable to have a table at the worksite so that the workpieces are stacked upon one another on that table. To accommodate this need, conscientious craftsmen attempt to fashion their own table. By necessity such a table must be long enough and wide enough for the cut workpieces. As a rule, such a table has a relatively cumbersome structure. Since equipment must be moved to new job sites, cumbersome tables are not desired. Therefore, it would be desirable to have the table that can be folded and/or easily transported and that would work efficiently to receive workpieces cut from the coil.
Furthermore, at least some of the components of the known bending machines may not be ergonomically designed and tend to make the craftsman's job rather difficult. For example, some of the known brakes have rulers used by the craftsman to mark a portion of the individual workpieces that has to be bent. As mentioned before, each workpiece is typically a few feet long. Accordingly, while the craftsman marks different regions of the single workpiece for further uniform cutting or bending, he/she moves along the workpiece. The rulers, which typically extend transversely to the longitudinal axis of the machine, tend to interfere with the craftsman's movement. It would be desirable to mount the rulers to the machine in a manner allowing the craftsman to swing them to a position, in which the rulers would not hinder the craftsman's work.
After the portion of the workpiece to be bent is uniformly marked, the craftsman clamps the workpiece between holding jaws and pivots them to an operative position, thereby bending the workpiece. Some of the known bending machines do not have a mechanism providing a positive lock between the holding jaws and workpiece. Others may be equipped with such a lock, but the structure of the lock may not be safe for the craftsman, who may have his/her fingers trapped in the lock, which can lead to devastating injuries. As a consequence, it is desirable to improve the known lock structures.
Many of the known bending machines also have a slitter operative to cut the workpiece parallel to its longitudinal axis so as to provide the workpiece with the desirable width. Upon cutting, a cutoff portion simply falls on the ground. The craftsman and his assistants, typically, pick up the fallen piece from the floor and put it back on the table for further bending operations, if the width of the cutoff portion allows for such an operation. Clearly, the efficiency of the process is reduced, since picking the cutoff portion from the floor and putting it on the table take a relatively long time. It would be advantageous to provide the bending machine with a support, which is attached to the machine and configured to catch the cutoff piece before it falls on the floor.
A need, therefore, exists for sheet bending brakes that operate in an efficient manner.
Another need exists for sheet bending brakes that have an ergonomically configured structure.
Another need exists for sheet bending brakes provided with a support that prevents falling cutoff pieces on the ground.
Still a further need exists for sheet bending brakes that have an easily foldable and transportable structure.